kernel: provide better control & help for SLUB configuration

Allow selecting KERNEL_SLUB_DEBUG and KERNEL_SLUB_DEBUG_ON manually and
provide detailed help for both.

Signed-off-by: Rafał Miłecki <rafal@milecki.pl>

diff --git a/config/Config-kernel.in b/config/Config-kernel.in
index a1209d82f3a8d11a028907939d4fb840e25142be..4c43190e40df5e9df12f83857bdb41250e700006 100644 (file)
--- a/config/Config-kernel.in
+++ b/config/Config-kernel.in
@@ -682,10 +682,23 @@ config KERNEL_PRINTK_TIME
        default y
 
 config KERNEL_SLUB_DEBUG
-       bool
+       bool "Enable SLUB debugging support"
+       help
+         This enables various debugging features:
+           - Accepts "slub_debug" kernel parameter
+           - Provides caches debugging options (e.g. tracing, validating)
+           - Adds /sys/kernel/slab/ attrs for reading amounts of *objects*
+           - Enables /proc/slabinfo support
+           - Prints info when running out of memory
+
+         Enabling this can result in a significant increase of code size.
 
 config KERNEL_SLUB_DEBUG_ON
-       bool
+       depends on KERNEL_SLUB_DEBUG
+       bool "Boot kernel with basic caches debugging enabled"
+       help
+         This enables by default sanity_checks, red_zone, poison and store_user
+         debugging options for all caches.
 
 config KERNEL_SLABINFO
        select KERNEL_SLUB_DEBUG